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Solar

Solar Thermal

Solar thermal energy uses the sun’s energy to heat water which compliments a traditional boiler and helps to reduce fuel bills by as much as 70% as well as helping the environment. Solar thermal hot water heating has been used in other European countries for many years but is still seen as being new in the UK. It has been used to great success all over the UK and is now regularly seen on our roof tops especially as all new-build properties must now have some form of renewable energy thanks to the Governments recent “code for sustainable homes”.

Solar thermal energy is the best known and most popular form of domestic renewable energy. The sun’s energy is collected by flat plate collectors or evacuated tubes (usually on the roof) which are orientated towards the sun in order to warm the property’s water. Inside the panels is a glycol mix which acts as anti-freeze in order to prevent freezing in cold periods whilst preventing it from boiling in especially hot spells. This hot fluid is then passed through a twin-coil cylinder (which looks very similar to traditional hot water cylinders, except for an additional flow and return that passes through the cylinder which helps to transfer the free heat from the sun into the cylinder which would otherwise just be heated by the boiler.

Manufacturers state that an average property should receive around 60-70% of the properties total hot water demands from solar thermal systems. Contrary to common belief, a lot of solar energy can still be gained from solar collectors even on cloudy days.

PhotoVoltaic Solar Panels

PhotoVoltaic, or PV, is a slightly newer technology than solar thermal and the principles are simple. A chemical reaction generates electrical current within the panels (which again are usually found on the roof of a building) and this electricity can then be used in the home to power appliances which have traditionally been solely reliant on the national grid and its fossil fuels.

The idea behind a typical domestic installation is to cover the “base load”. This covers appliances such as fridges, low level lighting and any other low demand but constant draws. It is not designed to cover all electrical demands such as kettles, irons etc as they have high power requirements and would require much larger PV installations.

Most households would normally install just enough to cover the basics and the national grid would then pick up the excess and peak demands. The Government has launched a scheme that offers clean energy cash back (via the Government's recently introduced feed-in tariff scheme) to householders who generate their own electricity which will be based on what is sold back to the national grid.